An innovative Weight-Bearing Device for Weight-Bearing Three-Dimensional Imaging for Foot and Ankle Surgery Pre-operative Planning

Abstract Three-dimensional preoperative planning has demonstratedmultiple surgical advantages. Currently, we cannot carry outpreoperative three-dimensional planning of foot and ankle orthopedics inmost hospitals due to the impossibility of performing weight-bearing CT imaging. Our objective is to describe and evaluate an innovative accessible,simple, and effective device that simulates standing while in a supineposition, to obtain three-dimensional images supporting bodyweightloadwith a conventional CT machine.From a group of 30 volunteers, 10 patients were randomly selected andpressure and its distribution were analyzed while in a standing position inboth feet. Differences between both feet were considered normal intrapersonal variability. Subsequently, the right footprint of the same 10 subjects was evaluated in the proposed loading device. Then, their pressures and distribution were compared with respect to standing and with respect to intrapersonal variability.The mean total standing pressure was 93 Kpa (SD 14.32), which was reduced to 81.95 Kpa (SD 19.54) in the loading device. The load device reduced the pressureby a mean of16% (SD 22% (range (- 25%) - (-0.03%)). At the hindfoot level, the loading device increased pressure by a mean of 20.59 Kpa, which expressed percentage implies an increase of 14% compared to standing.Due to its easy construction and effectiveness, this is the first device thatopens the door of foot and ankle orthopedics in any hospital to 3Dpreoperative planning and the benefits derived from it.